I really don't know if the tones produced are indeed at the right frequencies... It sounds right to me but I'm no expert

I'm not an expert too, but the generated tones are quite different from those generated by "dtmfdial"...
Based on what I found on http://www.hut.fi/~then/mytexts/dtmf_generation.html, I modified your prog :

for my $tone (@tones) {
  my @hz = map { 2 * $pi * $_ } @{$dtmf{$tone}};
  add_tone(@hz);
}
[download]

(note the factor '2')

and now I got (what I think to be) similar tones...
I also had to modify $duration to to have the exact same output as dtmfdial but that's just a detail


"Only Bad Coders Code Badly In Perl" (OBC2BIP)